In general, a capacitive-type fingerprint sensor array recognizes fingerprints in such a manner that when a users fingerprint comes into contact with a protective film disposed on a pixel electrode (sensing electrode), a difference in capacitance is generated depending on the unevenness of a fingerprint, and a pixel circuit detects the difference.
FIG. 1 and FIG. 2 are cross-sectional views of a sensor array according to a conventional art.
As illustrate in FIG. 1, a structure of the conventional sensor array includes a substrate 110, a pixel circuit 120, a pixel electrode (sensing electrode) 130, and a protective layer 140.
In general, the pixel circuit 120 is composed of a transistor, and the pixel electrode (sensing electrode) 130 is located at the top of the pixel circuit 120, so that a signal (a difference in capacitance) can be transmitted to the pixel circuit 120.
In the sensor array illustrated in FIG. 1, when the users finger comes into contact with the protective film formed on the pixel electrode (sensing electrode) 130, static electricity charged in the human body is discharged to the pixel electrode (sensing electrode) 130, and due to the static electricity, the pixel circuit 120 may be monetarily damaged or may have a reduced function.
To solve this problem, as illustrated in FIG. 2, in the conventional art, a method in which an antistatic wiring 150 is located higher than the pixel electrode 130 was used in order to protect the pixel electrode.
However, due to the elements such as the pixel electrode (sensing electrode) and the antistatic wiring, the conventional art is problematic in that the visibility of a display disposed in a lower part of the sensor array is reduced.